Hot-air turbine power plant



March 22, 1949. J. s. HAvERsTlcK HOT-` AIR ''URBINE POWER PLANT Filed Sept. 13, 1946 Y t 0 wm. n C .A v a MW@ hn 0 J Patented Mar. 22, 1949 John S. Haverstick, Kingwood Township, Hunterdon County, N. J., assignor to De Laval Steam Turbine Company, Trenton, N. J., a corporation of New Jersey Application September 13, 1946, Serial No. 696,825

This invention relates to turbine 'systems and particularly to systems utilizing hot driving gases.

This application is in part a continuation of my application Serial No. 501,101, filed September 3, 1943, and issued as Patent No. 2,438,635, March 30, 1948.

In the usual arrangement for driving a turbine by means of gases at high temperature, the air is first compressed, passed through a heat exchanger to receive heat from exhaust gases, and introduced into a combustion chamber in which fuel is burned therein. The products of combustion are then passed through one or more turbines and exhausted through the heat exchanger to pre-heat the compressed air. A serious drawback in any such system is that the products of combustion must pass through the 2 Claims.

l an extent as possible may be exhausted to the atmosphere.

Airpassages in the heat exchanger I0, conventionalized as a coll I 2, are provided with compressed air byJthe series arrangement of centrifugal compressors I4 and Il. By virtue of the counterflow in the heat exchanger, the comturbine or turbines, wherein they may cause both low grade fuels, which give rise to highly corrosive products, being thereby precluded.

"pressed air passes therefrom in high tempera- `ture condition to flow successively through the turbines 20, 24 and 2l arranged in series. The flow takes place in a fashion hereafter described. The air exhausted from the last stage passes through the connections 8 and 1 to the combustion chamber 2 previously described and to a second combustion chamber 3 to which fuel is admitted at 5 and which delivers its products 'of combustion through the connection s to an in- In accordance with the present invention, syschamber or chambers to secure the most effec-- tive utilization of al1 of the heat energy available. The foregoing objects of the invention, as well as other objects relating to details of arrangement and operation, will be apparent from thev following description read in conjunction with the accompanying drawing in which the ligure is a diagram showing a system provided in accordance with the present invention.

termediate point Il of the gas flow passage I.

The high pressure turbine 20 is shown as driving the compressor I8 through the shaft 22,

while intermediate pressure turbine 24 drives the first stage compressor I4 through the shaft 28. Power is taken from the low pressure turbine 2! through its shaft 3l. While this arrangement of the turbines is desirable since the high pressure turbine 20, operating at high speed, is properly suited to the driving of the second stage compressor, with the turbine 24, operating at lower speed, driving the rst stage compressor, and with the low pressure turbine operating at still lower speed and adapted for the delivery of mechanical power, the arrangement of the turbines is subject to considerable variation. The arrangement illustrated is, fur- There is illustrated in the ilgure a combustion .L

chamber 2 into which fuel is introduced at 4 to be burned in air admitted at 8. This combustion chamber may be of quite different types depending upon the fuel which is-burned. If the fuel is oil or gas it may be injected in the form of a jet or spray. If the fuel is nely powdered coal it may be similarly injected in dispersed form. On the other hand, the combustion chamber may involve the introduction of coal or other solid fuel in relatively large pieces, in which case a stoker may be used. In all cases the products of combustion pass through the gas passages of a heat exchanger Il, which passages are collectively conventionalized at l as a coil though it will be understood that the heat exchanger will normally take a conventional form thermore, desirable because an element of control may be involved by adjustment of thenozzles of the low pressure turbine.

It will be noted thatthe arrangement described involves the absence of products of combustion from the turbines,A while by reason of the series arrangement theentire exhaust air from the turbines will pass to the combustion chambers, giving a uniform exhaust condition not composed of independent streams as would be the case if the air was exhausted from two independently operating `turbines. n

`The use of two combustion chambers as shown `.with one of them discharging combustion gases into an intermediate part of the heat exchanger. combined'with counteriiow with the air. results ssineifectiveheatingoftheairtoahightem- 3 perature. The combustion chamber 3 -may be omitted', the exhaust air passing through the passage 'l being used without the additional heat to serve to heat incoming air from the compressms. i f

Preferably there of the type described in my application Serial No. 501,102. filed September 3, 1943 now abanare fused multiflow turbines turbines 'arranged in series, means for compressing air driven by at least one of the turbines, means forheating the air, means for directing the heated air to the turbines to drive the same, and means for burning fuel in air exhausted from the turbines, the means for heating the air utilizdoned. As pointed out in said application a tur bine for handling gases at high temperature may be desirably formed with two sets of blades and cooperating nozzles, one set beingy at a greater radius than the other. The turbines 20, 2l and 2l are ofthis character. Portions of the air at the respective. higher andlower temperatures enter through the passages 32 and u and are discharged' from the high pressure stage at and I8 respectively, then entering the next stage from which they are discharged'at ll and 42 respectively. After passing through the final stage 28 these two portions of the air are mixed by the junction of the discharge passages Il and v Il and now together through the passages i and I to the combustion chambers.

As pointed out in my application referred to above the pressures at corresponding stages of the turbine or turbines are the same; i. e.. the pressure at I2 is substantially that at Il, that at 8l is substantially thatat .that at Il is substantially that at l2, and the discharge pressures in the passages from'the last stage turbine 2l are ing the products of said combustion. each of said turbines being constructed to handle a plurality of streams of vheated air at substantially similar pressures but 'at different temperatures. and means providing such Vstreams of heated air from the air heating meansto the turbines.

'Y 2. A turbine system comprising a plurality oi turbines arrangedin series, means for compressing air driven by at least one of the turbines, means for heating the air, means for directing the heated air to the turbines to drive the same.

- and means for burning fuel in air exhausted from the turbines, the means for heating the air utilizing the products yoi' saidv combustion, each of said turbines being constructed to handle a plurality'of streams of heated air at substantially similar pressures but at different temperatures, means providing such streams of heated air from the air heating means to the turbines. and said means for heating the air involving an air passage, means for subjecting'the air in counterfiow arrangement to heat exchange with a stream of saidp'roducts of combustion, and means for adding to the last mentioned stream at an intermediate point thereof'an additional stream of said products oi' combustion. f .JOHN S.l HAVERSTICK.

'REFERENCES CITED The following references are of record in the file oi' this patentz FOREIGN, PATENTS Number LCountry y Date 520,654" Germany Mar; l'l, 1931 215,485 Switzerland Oct. 1, 1941 

